Hanjie Tan, Guoyou Sun, Mi Zhang, Jingyuan Zhao, Jiangao Ruan, Xing Gao (Xingming Observatory), report ~3.7 mag outburst in a known variable star ( 16.63 r ) which is 20.32 rmag in Pan-STARRS DR1 catalogue. The transient was discovered on several 120-s survey images ( limiting mag about 19.0 ) taken by Xing Gao at Xingming Observatory #3 ( N88 ) around Feb. 28.78536, 2021 UT using a unfiltered CCD ( 0.3-m f/3.6 reflector ). Images can be found at: http://xjltp.china-vo.org/xm54ht.html
XM54HT C2021 02 28.78536 08 05 49.66 +68 48 20.9 16.63 r N88
XM54HT C2021 02 28.80241 08 05 49.64 +68 48 19.3 16.59 r N88
*Known VS MASTER OT J080549.62+684821.0
